Chemical sampling sink

ABSTRACT

A chemical sampling sink and method. The chemical sampling sink typically includes an enclosure configured to contain a receptacle, and a chemical supply line extending into the enclosure, the chemical supply line including a dispenser configured to deliver a liquid chemical to the receptacle. The chemical sampling sink also includes an exhaust line attached to the enclosure, the exhaust line being configured to suction gases from the enclosure, and a filter positioned on the enclosure, the filter being configured to remove contaminants from air drawn into the enclosure as gases are suctioned from the enclosure out the exhaust line.

TECHNICAL FIELD

The present invention relates generally to chemical sampling sinks, andmore specifically to chemical sampling sinks for use in the siliconprocessing industry.

BACKGROUND

Chemical sampling sinks are used in a variety of industrial applicationsto take samples of chemicals in a controlled environment, free ofpollutants. In the semiconductor processing industry, chemical samplingsinks are used to take samples of high purity chemicals, such asammonium hydroxide, as a quality control measure. The samples areanalyzed to ensure that the purity of the chemical is within a desiredrange.

To prevent contaminants from entering the sample, current chemicalsampling sinks include an enclosure surrounding a liquid chemicaldispenser. The enclosure includes a door through which a receptacle maypass to be positioned below the dispenser. Once the receptacle isinserted, the door may be shut and chemical poured from the dispenser.

Current chemical sampling sinks include a drain to carry away spilled oroverflowing liquids, and an exhaust to draw air out of the enclosure.One problem with current chemical sampling sinks is that the exhaustsystems tend to draw contaminated air into the enclosure. In siliconprocessing environments, fine silicon dust, present in minute amounts inthe air, may find its way into the enclosure through gaps in theenclosure walls or door, thereby contaminating the sample. Othercontaminants, such as dirt and pollen, may also be drawn into theenclosure through the gaps. Because chemical sampling sinks are used totake samples of extremely high purity chemicals, even minute amounts ofcontaminants can ruin a sample.

Another problem with current chemical sampling sinks is that operatorsof the sinks are able to dispense chemical liquids into receptacleswhile the door of the enclosure is open. This may expose the sample toairborne contamination entering through the door into the enclosure. Inaddition, dangerous chemical droplets or gases may be released from thesampling sink through the open door into the environment and/or onto theoperator. Because many of the chemicals sampled with chemical samplingsinks are potentially harmful, uncontrolled release of these chemicalsis a potential environmental and health risk.

In addition, current chemical sampling sinks are translucent and allowultraviolet (UV) radiation to enter the interior of the sink and damagecomponents, or the sinks are made of material that deteriorates whenexposed to UV radiation. Finally, current chemical sampling sinks usepush-button valves, and require operators to continuously press thebuttons for lengthy periods of time in order to dispense a sample.

It would be desirable to provide a chemical sampling sink that does notdraw airborne contaminants into the enclosure, prevents dispensing ofchemicals with the door open, is UV-resistant, and/or does not requirean operator to press a button continuously for lengthy periods todispense a chemical.

SUMMARY

A chemical sampling sink and method are provided. The chemical samplingsink typically includes an enclosure configured to contain a receptacle,and a chemical supply line extending into the enclosure, the chemicalsupply line including a dispenser configured to deliver a liquidchemical to the receptacle. The chemical sampling sink also includes anexhaust line attached to the enclosure, the exhaust line beingconfigured to suction gases from the enclosure, and a filter positionedon the enclosure, the filter being configured to remove contaminantsfrom air drawn into the enclosure as gases are suctioned from theenclosure out the exhaust line. The sink may also have valves that donot require operators to continuously press a button to dispensechemicals, and the sinks may be made of a material that is UV resistant.Sinks that have new valves or that are UV resistant may or may notinclude a filter to remove contaminants from air drawn into theenclosure and sinks that include such a filter may or may not have newvalves or UV resistant material.

The method typically includes providing an enclosure, placing areceptacle within the enclosure, the receptacle being configured to holda chemical, dispensing a chemical through a dispenser into thereceptacle within the enclosure, suctioning gases from the enclosure toan exhaust line, and filtering air drawn into the enclosure duringsuctioning.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an isometric view of one embodiment of a chemical samplingsink according to the present invention.

FIG. 2 is an isometric view of the embodiment of FIG. 1, shown with anopen door.

FIG. 3 is a front view of another embodiment of a chemical sampling sinkaccording the present invention.

FIG. 4 is a cutaway isometric view of the embodiment of FIG. 1.

FIG. 5 is a cross-sectional elevation view taken along line 5—5 of FIG.4.

FIG. 6 is a cross-sectional plan view taken along line 6—6 of FIG. 5.

FIG. 7 is a partial cross-sectional elevation view taken along line 7—7of FIG. 6.

FIG. 8 is a cross-sectional plan view taken along line 8—8 of FIG. 5.

FIG. 9 is an isometric view of one embodiment of a filter assemblyaccording to the present invention.

FIG. 10 is a flowchart of a method according to the present invention.

DETAILED DESCRIPTION

Referring to FIG. 1, one embodiment of a chemical sampling sinkaccording to the present invention is shown generally at 10. Chemicalsampling sink 10 generally includes an enclosure 12, a chemical deliverysubsystem 14 including a plurality of chemical supply lines 15 extendinginto the enclosure, an exhaust line 16 configured to draw exhaust gasesfrom the enclosure, and a filter assembly 18 positioned in a wall of theenclosure. The filter assembly is configured to remove contaminants fromair drawn into the enclosure as gases are suctioned from the enclosurethrough exhaust line 16. Chemical sampling sink 10 also may include adrain 20 and water supply line 22. To take a sample of a chemical, areceptacle 28, shown in FIG. 2, may be placed within enclosure 12through an access door 24, and a sample quantity of liquid chemical maybe dispensed into the receptacle from a dispenser 30.

Enclosure 12 typically includes an outer wall 34 formed in the shape ofa box with rectangular sides. Alternatively, outer wall 34 may be formedin the shape of a cube, sphere, or virtually any other shape. Enclosure12 typically is formed from polypropylene. Alternatively, enclosure 12may be formed at least partially of metal, glass, and/or othermaterials, or may be formed of another type of plastic. Where chemicalsampling sink 10 is to be exposed to ultraviolet (UV) radiation, such asin outdoor applications, a dark or black plastic, such as blackpolypropylene may be used to reduce UV damage to the surface andinterior components.

As shown in FIG. 2, chemical sampling sink 10 also typically includes anaccess door 24 configured to vertically slide along tracks 26 between anopen configuration shown in FIG. 2, and a closed configuration, shown inFIG. 1. In the closed configuration, access door 24 typically rests inlongitudinal slot 26 a, shown in FIG. 5. In the open position, accessdoor 24 typically rests in slot 26 b, also shown in FIG. 5, and extendsupward above the top of the enclosure. Alternatively, the access doormay transition in a manner other than vertical sliding, such as byhinges, rotation, horizontal sliding, or other transition mechanism.

When access door 24 is in the open configuration, receptacle 28 may beplaced by an operator inside enclosure 12, and positioned adjacent toone of dispensers 30. Dispensers 30 are fed by respective chemicalsupply lines 15, and are configured to dispense liquid chemical intoreceptacle 28. After placing the receptacle in the enclosure, theoperator may close access door 24 to prevent accidental spillage of thechemical and unwanted entrance of airborne contaminants during thesampling process. Once the access door is closed, liquid chemical may bedispensed through dispenser 30 into receptacle 28 within thesubstantially contaminant-free interior of enclosure 12. The access doorthen may be opened, and the sample removed and processed.

As shown in FIG. 4, enclosure 12 also typically includes a samplingcompartment 32 positioned in the interior of the enclosure. Samplingcompartment 32 typically includes a floor 36, side walls 38, and aceiling 40. Floor 36 typically is perforated with holes 42 acrosssubstantially all of its surface. Alternatively, floor 36 may beperforated only in certain regions, or may contain only one hole or asmall number of holes. In addition, floor 36 typically includes largeholes 42 a, shown in FIG. 8, and may also include holes of various othersizes. The holes in floor 36 are configured to allow liquid chemicals,water, and gases to pass through floor 36 into a lower region 44.

Chemical delivery subsystem 14 typically includes a plurality ofchemical supply lines 15 configured to carry a variety of liquidchemicals used in silicon processing, including but not limited tohydrogen peroxide, ammonium hydroxide, acetic acid, nitric acid,hydrofluoric acid, hydrochloric acid, sulfuric acid, potassiumhydroxide, sodium hydroxide, and deionized water. Of course, onlycompatible chemicals should be grouped in a single sampling box. Theliquid chemicals are carried from a source (not shown) by chemicalsupply lines 15, through a plurality of conduits 48 to a service accesschamber 50. Service access chamber 50 includes a service door 52 whichmay be removed to allow an operator easy access to chemical supply lines15. Chemical supply lines 15 continue from service access chamber 50upward through a second conduit 54 into a rear right corner of enclosure12. Alternatively, chemical supply lines 15 may enter into enclosure 12in another location or manner, such as without conduits 48 and 54 orservice access chamber 50.

Typically, chemical supply lines 15 are made from a perfluoroalkoxy(PFA), which is resistant to chemical reaction. Alternatively, anotherfluoroplastic, or virtually any other material suitable to transport thechemical liquid without contamination or adverse chemical reaction, maybe used for chemical supply lines 15.

As shown in FIGS. 6-8, chemical supply lines 15 enter enclosure 12 fromsecond conduit 54 into a passthrough chamber 56. Passthrough chamber 56inhibits passage of drained liquids and gases from enclosure 12 intosecond conduit 54, and inhibits air from being drawn from second conduit54 into enclosure 12 by suction from exhaust line 16. Passthroughchamber 56 typically includes walls 58, a ceiling formed by plate 60,shown in FIG. 8, and a floor 61. Chemical supply lines 15 pass throughcorresponding holes in ceiling 60. Typically, passthrough chamber 56 isseparated from the remainder of the enclosure by a substantiallyairtight seal. Alternatively, a passthrough chamber with no seal may beused, or no passthrough chamber may be employed.

Turning now to FIG. 5, chemical supply lines 15 continue throughpassthrough chamber 56 and plate 60 into a rearward chamber 62. Each ofchemical supply lines 15 includes a dispenser 30 at an end, and isassociated with a corresponding valve 64.

Valves 64 each include an actuator 66 for regulating flow from achemical supply line 15 to a corresponding dispenser 30. The actuatormay be a handle that operates by turning. In one embodiment, valve 64 isa manual PFA two-way valve, sold under the part name MV10-1044-00-01,available from Parker Hannifin Corporation of Cleveland, Ohio. Arotatable handle enables an operator to dispense chemical withoutcontinuously depressing a push-button valve, as required by prior sinks.Alternatively, actuator 66 may be a button which operates by pushing inand out, or some other alternative form of actuator, such as a lever.The lever and button also may be configured such that an operator neednot hold the lever or button down continuously to dispense chemicals.

Actuators 66 typically are positioned within a recess 67 in the outersurface of enclosure 12. When access door 24 is in the openconfiguration, the access door covers the recess, and the actuatorspositioned therein, thereby inhibiting user access to the actuators.Therefore, the access door acts as a safety mechanism, and preventsdispensing of liquid chemical while the access door is open.Alternatively, the actuators may be positioned directly on the outsideof the enclosure 12, not in any recess, or in some other location.

Typically, dispenser 30 is a section of PFA tubing attached at a top endto valve 64 and extending into and hanging freely within samplingcompartment 32. A lower end of dispenser 30 extends through a notch 68in a guide plate 70, shown in FIGS. 2 and 4. Guide plate 70 typically ismounted to rear and side walls of sampling chamber 32. In one embodimentof the invention, guide plate 70 is vertically adjustable withinsampling compartment 32. Alternatively, the guide plate is fixed at apredetermined height.

The ends of dispensers 30 are configured to be positioned adjacentreceptacles 28 when receptacles 28 are placed within the enclosure forsampling. Typically, the dispensers extend to slightly above receptacles28. Alternatively, the dispensers extend into the receptacles, or arepositioned a predetermined distance above the receptacles such thatchemical flows from the a dispenser into a receptacle when an actuator66 of a valve 64 is manipulated.

Chemical sampling sink 10 also may include a sprayer 72, which receiveswater from water supply line 22, as shown in FIGS. 1 and 4. Typically,sprayer 72 is an elongated spray bar punctuated with holes, such thatwater sprays out from the bar in various directions into the samplingchamber. The sprayer may be actuated by an external valve (not shown),an actuator in recess 67, or some other control mechanism. For example,water supply line 22 may be routed through one of valves 64 such thatthe valve may be used to operate the spray bar. In operation, spray bar72 is configured to spray water throughout sampling chamber 32 to cleanany spilled chemicals or other contaminants from the chamber.

Water from the spray bar and liquid chemicals from the dispenser, aswell as gases from chemical sampling chamber 32 may pass throughperforations or holes 42 in floor 36 and into lower chamber 44. Lowerchamber 44 is configured to drain any liquids in the lower chamber downdrain line 20. The general flow of liquid down drain 20 is indicated byflow lines 80, in FIG. 4.

Exhaust line 16 is configured to include a suction creating device sucha pump or fan (not shown). Exhaust line 16 extends into enclosure 12through a top of the enclosure and extends through rearward chamber 62to terminate in plate 60. Plate 60 serves as a ceiling not only forpassthrough chamber 56, but also as a ceiling for a manifold chamber 76,shown in FIG. 6. Manifold chamber 76 is separated from passthroughchamber 56 by wall 58. Manifold chamber 76 and multiple passageways 74direct gases from the lower chamber to the exhaust line.

As gases are drawn out of enclosure 12 by exhaust line 16 and itsassociated suction source, gases are drawn from chemical samplingchamber 32 down thru-holes or perforations 42 in floor 36 into lowerchamber 44, through passageways 74 and into manifold chamber 76 and,finally, up through exhaust line 16 and out of enclosure 12, as shown inFIG. 4. The paths of the gases as they typically flow from the samplingchamber 32 to exhaust line 16 are indicated generally by exhaust flowlines 78.

As air is drawn out of enclosure 12 by exhaust line 16, subatmosphericpressure is created within enclosure 12. The difference in pressurewithin the enclosure and without the enclosure will tend to draw airinto the enclosure from outside the enclosure. Air may enter theenclosure through small gaps, cracks, or imperfect seals in the outersurface, door, joints, etc., of the enclosure.

To prevent airborne contaminants, such as silicon, dust, pollen, etc.,from being drawn into the chemical sampling chamber 32 and contaminatinga chemical sample, chemical sampling sink 10 includes a filter assemblyshown generally at 18 in FIG. 1. As shown in FIG. 9, filter assembly 18typically includes a filter box 82 configured to house a filter 84.Typically, filter box 82 is positioned inside on the access door of theenclosure, in a position indicated by dashed lines 86 in FIG. 1.Alternatively, filter box 82 may be mounted on an outside of the accessdoor, or elsewhere inside or outside enclosure 12. The filter box may bemounted to the sink in any manner, such as by an adhesive or by screws.

Filter box 82 typically includes a back plate 88 and a framework 90defining a sheath surrounding void 92. Void 92 is sized to receivefilter 84, and is open on one side such that filter 84 may slide out ofthe framework to be removed and replaced. Back plate 88 typicallyincludes thru-holes 94 which face outward from the enclosure.Alternatively, filter box 82 may be mounted to enclosure such that thethru-holes 94 face into the enclosure 12. Filter 84 alternatively may bemounted to the enclosure without a filter box, for example, by directlymounting the filter in an opening in the enclosure.

Typically, the filter is a standard dust filter. Alternatively, thefilter may be a High Efficiency Particulate Air (HEPA) filter. HEPAfilters are typically composed of thin pleated sheets of boron silicatemicrofibers, separated by aluminum separators that direct air flowthrough the sheets. HEPA filters typically remove about 99.95% ofparticles 0.3 micrometers or larger in diameter from a quantity of air.In addition, the filter may be another type of filter suitable to removea larger or smaller percentage of particles of the same or a differentsize.

Filter assembly 18 is configured to impede airflow into the enclosuresubstantially less than the combined impedance of other gaps, joints,seals, etc., in the enclosure. Therefore, substantially all of the airdrawn into the enclosure usually will pass through filter assembly 18.While typically the filter assembly includes three thru-holes,alternatively the filter assembly may include a larger or smaller numberof thru-holes. The thru-holes are depicted as oval in shape, but itshould be understood that the thru-holes may be of virtually any sizeand shape so long as air may pass through the thru-holes through thefilter.

Referring now to FIG. 3, another embodiment of chemical sampling sinkaccording to the present invention is shown generally at 110. Chemicalsampling sink 110 includes an enclosure 112 having a plurality ofindividually openable access doors 114. Typically, each access doorincludes a filter assembly 116, each filter assembly having a pluralityof thru-holes 118 and an associated filter, as described above.Alternatively, one or more of the doors may not include a filterassembly, and/or the doors may include a filter assembly with a greateror lesser number of thru-holes. When each door 114 is in the openconfiguration, it is positioned in front of a corresponding set ofactuators 120 such that the actuators are difficult or impossible tomanipulate when the access door is opened. As shown at 120 a, one ormore of the actuators may be a lever configured to rotate around a pivotpoint. Closing the access door exposes the actuators 120, therebyenabling an operator to dispense chemical into a receptacle.

As shown in FIG. 10, a method 200 for sampling a chemical may bepracticed according to the present invention. At 202, the methodincludes providing an enclosure. The enclosure may include an accessdoor, and a filter may be positioned within the access door, orelsewhere on the enclosure, as described above. The enclosure may alsoinclude a sampling compartment separated from a lower chamber by aperforated floor, and a manifold chamber fluidically connecting thelower chamber to an exhaust line, as described above.

At 204, the method includes placing a receptacle configured to hold aliquid chemical within the enclosure. Placing may be accomplished bypositioning the access door in an open configuration in which the accessdoor at least partially inhibits user access to an actuator of thevalve, and inserting the receptacle into the interior of the enclosureadjacent a dispenser. The actuator may be positioned in a recess, andmay be a handle or button, as described above.

At 206, the method includes dispensing a chemical through a dispenserinto the receptacle within the enclosure. At 208, the method includessuctioning gases from the enclosure to an exhaust line. Suctioning mayinclude drawing air from the sampling compartment to the lower chamberthrough the perforated floor, from the lower chamber through themanifold chamber, and out the exhaust line. Suctioning may be performedbefore, after, and/or during the dispensing.

At 210, the method includes filtering air drawn into the enclosureduring suctioning. Typically, filtering includes drawing air into theenclosure by suctioning from the exhaust line, and passing air through afilter positioned in a wall of the enclosure. The filtered air typicallytravels according to the path described above and shown at 208.

According to the present invention, a chemical sampling sink and methodare provided that inhibit entry of airborne contaminants air into theenclosure, inhibit dispensation of liquid chemical with an open door,inhibit UV damage to the surface and internal components, and/or may beoperated without continuously depressing a button.

Industrial Applicability

This invention is applicable to industrial chemical applications, andparticularly to chemical sampling in the semiconductor processingindustry.

While the invention has been disclosed in its preferred form or forms,the specific embodiments thereof as disclosed and illustrated herein arenot to be considered in a limiting sense as numerous variations arepossible. The subject matter of the invention includes all novel andnon-obvious combinations and subcombinations of the various elements,features, functions and/or properties disclosed herein. No singlefeature, function, element or property of the disclosed embodiments isessential. The following claims define certain combinations andsubcombinations which are regarded as novel and non-obvious. Othercombinations and subcombinations of features, functions, elements and/orproperties may be claimed through amendment of the present claims orpresentation of new claims in this or a related application. Such claimsalso are regarded as included within the subject matter of the presentinvention irrespective of whether they are broader, narrower, equal, ordifferent in scope to the original claims.

We claim:
 1. A chemical sampling sink comprising: an enclosure definingan internal cavity and configured to maintain an atmosphere within theinternal cavity, the enclosure also configured to contain a receptaclesuch that a liquid chemical within the receptacle would be exposed tothe atmosphere, wherein the enclosure is made of dark, UV-resistantplastic; a chemical supply line extending into the enclosure, thechemical supply line including a dispenser configured to deliver aliquid chemical to the receptacle; an exhaust line attached to theenclosure, the exhaust line being configured to suction gases from theenclosure; and a filter positioned on the enclosure, the filter beingconfigured to remove contaminants from air drawn into the enclosure asgases are suctioned from the enclosure out the exhaust line to therebyprevent the removed contaminants from entering the atmosphere in theenclosure and contaminating the liquid chemical in the receptacle. 2.The chemical sampling sink of claim 1, where the enclosure includes asampling compartment including a perforated floor.
 3. The chemicalsampling sink of claim 2, further comprising a drain below theperforated floor.
 4. The chemical sampling sink of claim 2, where theenclosure includes a lower chamber below the perforated floor, theexhaust line being fluidically connected to the sampling chamber throughthe perforated floor and lower chamber.
 5. The chemical sampling sink ofclaim 4, where the enclosure further includes a manifold chamberadjacent the lower chamber, the exhaust line being fluidically connectedto the sampling compartment through the lower chamber and the manifoldchamber.
 6. The chemical sampling sink of claim 5, where the manifoldchamber is fluidically connected by a plurality of passageways to thelower chamber, and where the exhaust line is configured to suction gasesfrom the enclosure such that air is drawn into the sampling compartmentthrough the filter, from the sampling compartment to the lower chamberthrough the perforated floor, from the lower chamber to the manifoldchamber through the passageways, and out of the enclosure through theexhaust line.
 7. The chemical sampling sink of claim 1, where the filteris positioned in a wall of the enclosure.
 8. The chemical sampling sinkof claim 1, where the enclosure includes an access door and the filteris positioned in the access door.
 9. The chemical sampling sink of claim1, where the enclosure includes a plurality of access doors.
 10. Thechemical sampling sink of claim 9, further comprising a filterpositioned in each access door.
 11. The chemical sampling sink of claim1, where the filter is removably mounted in a filter box.
 12. Thechemical sampling sink of claim 11, where the filter box includes aplurality of thru-holes through which air may pass.
 13. The chemicalsampling sink of claim 11, where the filter box includes a sheathconfigured to hold the filter.
 14. The chemical sampling sink of claim1, where the filter is a HEPA filter.
 15. The chemical sampling sink ofclaim 1, where the enclosure is substantially sealed, such thatsubstantially all of the air drawn into the enclosure as the gases aresuctioned out the exhaust line is drawn through the filter.
 16. Thechemical sampling sink of claim 1, further comprising a valve associatedwith the chemical supply line, the valve including a rotatable handleconfigured to regulate flow of liquid chemical through the chemicalsupply line to the dispenser.
 17. The chemical sampling sink of claim16, where the enclosure includes an access door configured to transitionbetween an open configuration and a closed configuration, the accessdoor being configured to partially cover the rotatable handle when theaccess door is in the open configuration.
 18. A method of sampling achemical, comprising: providing an enclosure defining an internal cavityand configured to maintain an atmosphere within the internal cavity,wherein the enclosure is made of dark, UV-resistant plastic; placing areceptacle within the enclosure, the receptacle being configured to holda chemical such that the chemical within the receptacle is exposed tothe atmosphere within the internal cavity; dispensing a chemical througha dispenser into the receptacle within the enclosure; suctioning gasesfrom the enclosure to an exhaust line; and filtering air drawn into theenclosure during suctioning to thereby prevent contaminants fromentering the atmosphere within the internal cavity.
 19. A chemicalsampling sink comprising: an enclosure made of dark, UV-resistantplastic; a transportable receptacle adapted to be inserted into andremoved from the enclosure; a chemical supply line extending into theenclosure, the chemical supply line including a dispenser configured todeliver a liquid chemical to the receptacle while the receptacle isdisposed in the enclosure; an exhaust line attached to the enclosure,the exhaust line being configured to suction gases from the enclosure;and filter means for removing contaminants from air drawn into theenclosure as gases are suctioned from the enclosure out the exhaustline.
 20. A chemical sampling sink comprising: an enclosure configuredto contain a receptacle; a chemical supply line extending into theenclosure, the chemical supply line including a dispenser configured todeliver a liquid chemical to the receptacle; a valve associated with thechemical supply line, the valve including a handle configured toregulate flow of liquid chemical through the chemical supply line to thedispenser; an access door positioned on the enclosure, the access doorbeing configured to transition between an open configuration and aclosed configuration such that the access door at least partially coversthe handle when in the open configuration; and an exhaust line attachedto the enclosure, the exhaust line being configured to suction gasesfrom the enclosure.
 21. The chemical sampling sink of claim 20, wherethe enclosure is configured to maintain an atmosphere such that a liquidchemical within the receptacle would be exposed to the atmosphere, thechemical sampling sink further comprising a filter positioned on theenclosure and configured to remove contaminants from air drawn into theenclosure as gases are suctioned from the enclosure out the exhaust lineto thereby prevent the removed contaminants from entering the atmospherein the enclosure and contaminating the liquid chemical in thereceptacle.
 22. A chemical sampling sink comprising: an enclosuredefining an internal cavity and configured to maintain an atmospherewithin the internal cavity, the enclosure also configured to contain areceptacle such that a liquid chemical within the receptacle would beexposed to the atmosphere, where the enclosure includes an access doorconfigured to transition between an open configuration and a closedconfiguration; a chemical supply line extending into the enclosure, thechemical supply line including a dispenser configured to deliver aliquid chemical to the receptacle; a valve associated with the chemicalsupply line, the valve including a rotatable handle configured toregulate flow of liquid chemical through the chemical supply line to thedispenser, where the access door of the enclosure is configured topartially cover the rotatable handle when the access door is in the openconfiguration; an exhaust line attached to the enclosure, the exhaustline being configured to suction gases from the enclosure; and a filterpositioned on the enclosure, the filter being configured to removecontaminants from air drawn into the enclosure as gases are suctionedfrom the enclosure out the exhaust line to thereby prevent the removedcontaminants from entering the atmosphere in the enclosure andcontaminating the liquid chemical in the receptacle.
 23. The chemicalsampling sink of claim 22, where the enclosure includes a samplingcompartment including a perforated floor.
 24. The chemical sampling sinkof claim 23, further comprising a drain below the perforated floor. 25.The chemical sampling sink of claim 23, where the enclosure includes alower chamber below the perforated floor, the exhaust line beingfluidically connected to the sampling chamber through the perforatedfloor and lower chamber.
 26. The chemical sampling sink of claim 25,where the enclosure further includes a manifold chamber adjacent thelower chamber, the exhaust line being fluidically connected to thesampling compartment through the lower chamber and the manifold chamber.27. The chemical sampling sink of claim 26, where the manifold chamberis fluidically connected by a plurality of passageways to the lowerchamber, and where the exhaust line is configured to suction gases fromthe enclosure such that air is drawn into the sampling compartmentthrough the filter, from the sampling compartment to the lower chamberthrough the perforated floor, from the lower chamber to the manifoldchamber through the passageways, and out of the enclosure through theexhaust line.
 28. The chemical sampling sink of claim 22, where thefilter is positioned in a wall of the enclosure.
 29. The chemicalsampling sink of claim 22, where the enclosure includes an access doorand the filter is positioned in the access door.
 30. The chemicalsampling sink of claim 22, where the enclosure includes a plurality ofaccess doors.
 31. The chemical sampling sink of claim 30, furthercomprising a filter positioned in each access door.
 32. The chemicalsampling sink of claim 22, where the filter is removably mounted in afilter box.
 33. The chemical sampling sink of claim 32, where the filterbox includes a plurality of thru-holes through which air may pass. 34.The chemical sampling sink of claim 32, where the filter box includes asheath configured to hold the filter.
 35. The chemical sampling sink ofclaim 22, where the filter is a HEPA filter.
 36. The chemical samplingsink of claim 22, where the enclosure is substantially sealed, such thatsubstantially all of the air drawn into the enclosure as the gases aresuctioned out the exhaust line is drawn through the filter.
 37. Thechemical sampling sink of claim 22, where the enclosure is made of dark,UV-resistant plastic.
 38. A chemical sampling sink comprising: anenclosure, where the enclosure includes an access door configured totransition between an open configuration and a closed configuration; atransportable receptacle adapted to be inserted into and removed fromthe enclosure; a chemical supply line extending into the enclosure, thechemical supply line including a dispenser configured to deliver aliquid chemical to the receptacle while the receptacle is disposed inthe enclosure; a valve associated with the chemical supply line, thevalve including a rotatable handle configured to regulate flow of liquidchemical through the chemical supply line to the dispenser, where theaccess door of the enclosure is configured to partially cover therotatable handle when the access door is in the open configuration; anexhaust line attached to the enclosure, the exhaust line beingconfigured to suction gases from the enclosure; and filter means forremoving contaminants from air drawn into the enclosure as gases aresuctioned from the enclosure out the exhaust line.